2022 - Evaluation of Commercial Fluoride-Containing Products for HF using pH and Varied Sample Treatment - Poster Presentation

Authors: Peter Iles, Rochelle Lambersten, Sarah Moore, Muntadher AlAzzawi, Jared Thompson, Nadia Yahyapour, Dillon Reynolds, Grace Froh, Christopher Peak, Ron Valcarce, Rajan Kochambilli, Welsey Sanders. A number of commercial products containing fluoride have been analyzed by our research team, Such products include mouthwash, dental varnish, tablets, drops, gel and foam. The use of these materials are common dental treatments used to prevent and reverse demineralization and tooth decaying processes. Previous research showed a FIA system employing an Ion-Selective Electrode as the ion detector to be a fast measurement method for low level fluoride samples with ease of application for these samples. This new study is to evaluate if HF is present in the foam and gel samples as suggested on the label and to investigate the presence of fluoro-metal complexes. Two approaches to evaluate this problem were taken. Firstly, by measuring the pH of the sample and secondly via the speciation study the amount of HF was calculated via the buffer equation. The pH proved difficult to measure due to the physical nature of the samples. Fluoride Speciation was achieved by varying the sample treatment of the samples. The use of a nonbuffered ionic strength adjuster, a buffered treatment, and a buffer containing CDTA ligand enables the F- content of all three speciation types . Both samples were found to contain Free F-, HF, and significant amounts of F- bound to metal ions as complex ions. The results have implications for the efficacy and shelf life of the products.